1 files changed, 267 insertions, 119 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 5c469c1dfb8b..f8f3bfc435ee 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -522,12 +522,6 @@ static void bad_page(struct page *page, const char *reason,
 	static unsigned long nr_shown;
 	static unsigned long nr_unshown;
 
-	/* Don't complain about poisoned pages */
-	if (PageHWPoison(page)) {
-		page_mapcount_reset(page); /* remove PageBuddy */
-		return;
-	}
-
 	/*
 	 * Allow a burst of 60 reports, then keep quiet for that minute;
 	 * or allow a steady drip of one report per second.
@@ -613,14 +607,7 @@ static int __init early_debug_pagealloc(char *buf)
 {
 	if (!buf)
 		return -EINVAL;
-
-	if (strcmp(buf, "on") == 0)
-		_debug_pagealloc_enabled = true;
-
-	if (strcmp(buf, "off") == 0)
-		_debug_pagealloc_enabled = false;
-
-	return 0;
+	return kstrtobool(buf, &_debug_pagealloc_enabled);
 }
 early_param("debug_pagealloc", early_debug_pagealloc);
 
@@ -1000,7 +987,6 @@ static __always_inline bool free_pages_prepare(struct page *page,
 
 	trace_mm_page_free(page, order);
 	kmemcheck_free_shadow(page, order);
-	kasan_free_pages(page, order);
 
 	/*
 	 * Check tail pages before head page information is cleared to
@@ -1042,6 +1028,7 @@ static __always_inline bool free_pages_prepare(struct page *page,
 	arch_free_page(page, order);
 	kernel_poison_pages(page, 1 << order, 0);
 	kernel_map_pages(page, 1 << order, 0);
+	kasan_free_pages(page, order);
 
 	return true;
 }
@@ -1212,7 +1199,7 @@ static inline void init_reserved_page(unsigned long pfn)
  * marks the pages PageReserved. The remaining valid pages are later
  * sent to the buddy page allocator.
  */
-void __meminit reserve_bootmem_region(unsigned long start, unsigned long end)
+void __meminit reserve_bootmem_region(phys_addr_t start, phys_addr_t end)
 {
 	unsigned long start_pfn = PFN_DOWN(start);
 	unsigned long end_pfn = PFN_UP(end);
@@ -1661,6 +1648,9 @@ static void check_new_page_bad(struct page *page)
 	if (unlikely(page->flags & __PG_HWPOISON)) {
 		bad_reason = "HWPoisoned (hardware-corrupted)";
 		bad_flags = __PG_HWPOISON;
+		/* Don't complain about hwpoisoned pages */
+		page_mapcount_reset(page); /* remove PageBuddy */
+		return;
 	}
 	if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_PREP)) {
 		bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag set";
@@ -2750,10 +2740,9 @@ static inline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
  * one free page of a suitable size. Checking now avoids taking the zone lock
  * to check in the allocation paths if no pages are free.
  */
-static bool __zone_watermark_ok(struct zone *z, unsigned int order,
-			unsigned long mark, int classzone_idx,
-			unsigned int alloc_flags,
-			long free_pages)
+bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
+			 int classzone_idx, unsigned int alloc_flags,
+			 long free_pages)
 {
 	long min = mark;
 	int o;
@@ -3180,34 +3169,33 @@ out:
 	return page;
 }
 
+
+/*
+ * Maximum number of compaction retries wit a progress before OOM
+ * killer is consider as the only way to move forward.
+ */
+#define MAX_COMPACT_RETRIES 16
+
 #ifdef CONFIG_COMPACTION
 /* Try memory compaction for high-order allocations before reclaim */
 static struct page *
 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
 		unsigned int alloc_flags, const struct alloc_context *ac,
-		enum migrate_mode mode, int *contended_compaction,
-		bool *deferred_compaction)
+		enum migrate_mode mode, enum compact_result *compact_result)
 {
-	unsigned long compact_result;
 	struct page *page;
+	int contended_compaction;
 
 	if (!order)
 		return NULL;
 
 	current->flags |= PF_MEMALLOC;
-	compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac,
-						mode, contended_compaction);
+	*compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac,
+						mode, &contended_compaction);
 	current->flags &= ~PF_MEMALLOC;
 
-	switch (compact_result) {
-	case COMPACT_DEFERRED:
-		*deferred_compaction = true;
-		/* fall-through */
-	case COMPACT_SKIPPED:
+	if (*compact_result <= COMPACT_INACTIVE)
 		return NULL;
-	default:
-		break;
-	}
 
 	/*
 	 * At least in one zone compaction wasn't deferred or skipped, so let's
@@ -3233,19 +3221,112 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
 	 */
 	count_vm_event(COMPACTFAIL);
 
+	/*
+	 * In all zones where compaction was attempted (and not
+	 * deferred or skipped), lock contention has been detected.
+	 * For THP allocation we do not want to disrupt the others
+	 * so we fallback to base pages instead.
+	 */
+	if (contended_compaction == COMPACT_CONTENDED_LOCK)
+		*compact_result = COMPACT_CONTENDED;
+
+	/*
+	 * If compaction was aborted due to need_resched(), we do not
+	 * want to further increase allocation latency, unless it is
+	 * khugepaged trying to collapse.
+	 */
+	if (contended_compaction == COMPACT_CONTENDED_SCHED
+		&& !(current->flags & PF_KTHREAD))
+		*compact_result = COMPACT_CONTENDED;
+
 	cond_resched();
 
 	return NULL;
 }
+
+static inline bool
+should_compact_retry(struct alloc_context *ac, int order, int alloc_flags,
+		     enum compact_result compact_result, enum migrate_mode *migrate_mode,
+		     int compaction_retries)
+{
+	int max_retries = MAX_COMPACT_RETRIES;
+
+	if (!order)
+		return false;
+
+	/*
+	 * compaction considers all the zone as desperately out of memory
+	 * so it doesn't really make much sense to retry except when the
+	 * failure could be caused by weak migration mode.
+	 */
+	if (compaction_failed(compact_result)) {
+		if (*migrate_mode == MIGRATE_ASYNC) {
+			*migrate_mode = MIGRATE_SYNC_LIGHT;
+			return true;
+		}
+		return false;
+	}
+
+	/*
+	 * make sure the compaction wasn't deferred or didn't bail out early
+	 * due to locks contention before we declare that we should give up.
+	 * But do not retry if the given zonelist is not suitable for
+	 * compaction.
+	 */
+	if (compaction_withdrawn(compact_result))
+		return compaction_zonelist_suitable(ac, order, alloc_flags);
+
+	/*
+	 * !costly requests are much more important than __GFP_REPEAT
+	 * costly ones because they are de facto nofail and invoke OOM
+	 * killer to move on while costly can fail and users are ready
+	 * to cope with that. 1/4 retries is rather arbitrary but we
+	 * would need much more detailed feedback from compaction to
+	 * make a better decision.
+	 */
+	if (order > PAGE_ALLOC_COSTLY_ORDER)
+		max_retries /= 4;
+	if (compaction_retries <= max_retries)
+		return true;
+
+	return false;
+}
 #else
 static inline struct page *
 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
 		unsigned int alloc_flags, const struct alloc_context *ac,
-		enum migrate_mode mode, int *contended_compaction,
-		bool *deferred_compaction)
+		enum migrate_mode mode, enum compact_result *compact_result)
 {
+	*compact_result = COMPACT_SKIPPED;
 	return NULL;
 }
+
+static inline bool
+should_compact_retry(struct alloc_context *ac, unsigned int order, int alloc_flags,
+		     enum compact_result compact_result,
+		     enum migrate_mode *migrate_mode,
+		     int compaction_retries)
+{
+	struct zone *zone;
+	struct zoneref *z;
+
+	if (!order || order > PAGE_ALLOC_COSTLY_ORDER)
+		return false;
+
+	/*
+	 * There are setups with compaction disabled which would prefer to loop
+	 * inside the allocator rather than hit the oom killer prematurely.
+	 * Let's give them a good hope and keep retrying while the order-0
+	 * watermarks are OK.
+	 */
+	for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
+					ac->nodemask) {
+		if (zone_watermark_ok(zone, 0, min_wmark_pages(zone),
+					ac_classzone_idx(ac), alloc_flags))
+			return true;
+	}
+	return false;
+}
 #endif /* CONFIG_COMPACTION */
 
 /* Perform direct synchronous page reclaim */
@@ -3377,6 +3458,101 @@ static inline bool is_thp_gfp_mask(gfp_t gfp_mask)
 	return (gfp_mask & (GFP_TRANSHUGE | __GFP_KSWAPD_RECLAIM)) == GFP_TRANSHUGE;
 }
 
+/*
+ * Maximum number of reclaim retries without any progress before OOM killer
+ * is consider as the only way to move forward.
+ */
+#define MAX_RECLAIM_RETRIES 16
+
+/*
+ * Checks whether it makes sense to retry the reclaim to make a forward progress
+ * for the given allocation request.
+ * The reclaim feedback represented by did_some_progress (any progress during
+ * the last reclaim round) and no_progress_loops (number of reclaim rounds without
+ * any progress in a row) is considered as well as the reclaimable pages on the
+ * applicable zone list (with a backoff mechanism which is a function of
+ * no_progress_loops).
+ *
+ * Returns true if a retry is viable or false to enter the oom path.
+ */
+static inline bool
+should_reclaim_retry(gfp_t gfp_mask, unsigned order,
+		     struct alloc_context *ac, int alloc_flags,
+		     bool did_some_progress, int no_progress_loops)
+{
+	struct zone *zone;
+	struct zoneref *z;
+
+	/*
+	 * Make sure we converge to OOM if we cannot make any progress
+	 * several times in the row.
+	 */
+	if (no_progress_loops > MAX_RECLAIM_RETRIES)
+		return false;
+
+	/*
+	 * Keep reclaiming pages while there is a chance this will lead somewhere.
+	 * If none of the target zones can satisfy our allocation request even
+	 * if all reclaimable pages are considered then we are screwed and have
+	 * to go OOM.
+	 */
+	for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
+					ac->nodemask) {
+		unsigned long available;
+		unsigned long reclaimable;
+
+		available = reclaimable = zone_reclaimable_pages(zone);
+		available -= DIV_ROUND_UP(no_progress_loops * available,
+					  MAX_RECLAIM_RETRIES);
+		available += zone_page_state_snapshot(zone, NR_FREE_PAGES);
+
+		/*
+		 * Would the allocation succeed if we reclaimed the whole
+		 * available?
+		 */
+		if (__zone_watermark_ok(zone, order, min_wmark_pages(zone),
+				ac_classzone_idx(ac), alloc_flags, available)) {
+			/*
+			 * If we didn't make any progress and have a lot of
+			 * dirty + writeback pages then we should wait for
+			 * an IO to complete to slow down the reclaim and
+			 * prevent from pre mature OOM
+			 */
+			if (!did_some_progress) {
+				unsigned long writeback;
+				unsigned long dirty;
+
+				writeback = zone_page_state_snapshot(zone,
+								     NR_WRITEBACK);
+				dirty = zone_page_state_snapshot(zone, NR_FILE_DIRTY);
+
+				if (2*(writeback + dirty) > reclaimable) {
+					congestion_wait(BLK_RW_ASYNC, HZ/10);
+					return true;
+				}
+			}
+
+			/*
+			 * Memory allocation/reclaim might be called from a WQ
+			 * context and the current implementation of the WQ
+			 * concurrency control doesn't recognize that
+			 * a particular WQ is congested if the worker thread is
+			 * looping without ever sleeping. Therefore we have to
+			 * do a short sleep here rather than calling
+			 * cond_resched().
+			 */
+			if (current->flags & PF_WQ_WORKER)
+				schedule_timeout_uninterruptible(1);
+			else
+				cond_resched();
+
+			return true;
+		}
+	}
+
+	return false;
+}
+
 static inline struct page *
 __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
 						struct alloc_context *ac)
@@ -3384,11 +3560,11 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
 	bool can_direct_reclaim = gfp_mask & __GFP_DIRECT_RECLAIM;
 	struct page *page = NULL;
 	unsigned int alloc_flags;
-	unsigned long pages_reclaimed = 0;
 	unsigned long did_some_progress;
 	enum migrate_mode migration_mode = MIGRATE_ASYNC;
-	bool deferred_compaction = false;
-	int contended_compaction = COMPACT_CONTENDED_NONE;
+	enum compact_result compact_result;
+	int compaction_retries = 0;
+	int no_progress_loops = 0;
 
 	/*
 	 * In the slowpath, we sanity check order to avoid ever trying to
@@ -3475,8 +3651,7 @@ retry:
 	 */
 	page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags, ac,
 					migration_mode,
-					&contended_compaction,
-					&deferred_compaction);
+					&compact_result);
 	if (page)
 		goto got_pg;
 
@@ -3489,35 +3664,19 @@ retry:
 		 * to heavily disrupt the system, so we fail the allocation
 		 * instead of entering direct reclaim.
 		 */
-		if (deferred_compaction)
-			goto nopage;
-
-		/*
-		 * In all zones where compaction was attempted (and not
-		 * deferred or skipped), lock contention has been detected.
-		 * For THP allocation we do not want to disrupt the others
-		 * so we fallback to base pages instead.
-		 */
-		if (contended_compaction == COMPACT_CONTENDED_LOCK)
+		if (compact_result == COMPACT_DEFERRED)
 			goto nopage;
 
 		/*
-		 * If compaction was aborted due to need_resched(), we do not
-		 * want to further increase allocation latency, unless it is
-		 * khugepaged trying to collapse.
+		 * Compaction is contended so rather back off than cause
+		 * excessive stalls.
 		 */
-		if (contended_compaction == COMPACT_CONTENDED_SCHED
-			&& !(current->flags & PF_KTHREAD))
+		if(compact_result == COMPACT_CONTENDED)
 			goto nopage;
 	}
 
-	/*
-	 * It can become very expensive to allocate transparent hugepages at
-	 * fault, so use asynchronous memory compaction for THP unless it is
-	 * khugepaged trying to collapse.
-	 */
-	if (!is_thp_gfp_mask(gfp_mask) || (current->flags & PF_KTHREAD))
-		migration_mode = MIGRATE_SYNC_LIGHT;
+	if (order && compaction_made_progress(compact_result))
+		compaction_retries++;
 
 	/* Try direct reclaim and then allocating */
 	page = __alloc_pages_direct_reclaim(gfp_mask, order, alloc_flags, ac,
@@ -3529,14 +3688,38 @@ retry:
 	if (gfp_mask & __GFP_NORETRY)
 		goto noretry;
 
-	/* Keep reclaiming pages as long as there is reasonable progress */
-	pages_reclaimed += did_some_progress;
-	if ((did_some_progress && order <= PAGE_ALLOC_COSTLY_ORDER) ||
-	    ((gfp_mask & __GFP_REPEAT) && pages_reclaimed < (1 << order))) {
-		/* Wait for some write requests to complete then retry */
-		wait_iff_congested(ac->preferred_zoneref->zone, BLK_RW_ASYNC, HZ/50);
+	/*
+	 * Do not retry costly high order allocations unless they are
+	 * __GFP_REPEAT
+	 */
+	if (order > PAGE_ALLOC_COSTLY_ORDER && !(gfp_mask & __GFP_REPEAT))
+		goto noretry;
+
+	/*
+	 * Costly allocations might have made a progress but this doesn't mean
+	 * their order will become available due to high fragmentation so
+	 * always increment the no progress counter for them
+	 */
+	if (did_some_progress && order <= PAGE_ALLOC_COSTLY_ORDER)
+		no_progress_loops = 0;
+	else
+		no_progress_loops++;
+
+	if (should_reclaim_retry(gfp_mask, order, ac, alloc_flags,
+				 did_some_progress > 0, no_progress_loops))
+		goto retry;
+
+	/*
+	 * It doesn't make any sense to retry for the compaction if the order-0
+	 * reclaim is not able to make any progress because the current
+	 * implementation of the compaction depends on the sufficient amount
+	 * of free memory (see __compaction_suitable)
+	 */
+	if (did_some_progress > 0 &&
+			should_compact_retry(ac, order, alloc_flags,
+				compact_result, &migration_mode,
+				compaction_retries))
 		goto retry;
-	}
 
 	/* Reclaim has failed us, start killing things */
 	page = __alloc_pages_may_oom(gfp_mask, order, ac, &did_some_progress);
@@ -3544,19 +3727,28 @@ retry:
 		goto got_pg;
 
 	/* Retry as long as the OOM killer is making progress */
-	if (did_some_progress)
+	if (did_some_progress) {
+		no_progress_loops = 0;
 		goto retry;
+	}
 
 noretry:
 	/*
-	 * High-order allocations do not necessarily loop after
-	 * direct reclaim and reclaim/compaction depends on compaction
-	 * being called after reclaim so call directly if necessary
+	 * High-order allocations do not necessarily loop after direct reclaim
+	 * and reclaim/compaction depends on compaction being called after
+	 * reclaim so call directly if necessary.
+	 * It can become very expensive to allocate transparent hugepages at
+	 * fault, so use asynchronous memory compaction for THP unless it is
+	 * khugepaged trying to collapse. All other requests should tolerate
+	 * at least light sync migration.
 	 */
+	if (is_thp_gfp_mask(gfp_mask) && !(current->flags & PF_KTHREAD))
+		migration_mode = MIGRATE_ASYNC;
+	else
+		migration_mode = MIGRATE_SYNC_LIGHT;
 	page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags,
 					    ac, migration_mode,
-					    &contended_compaction,
-					    &deferred_compaction);
+					    &compact_result);
 	if (page)
 		goto got_pg;
 nopage:
@@ -6671,49 +6863,6 @@ void setup_per_zone_wmarks(void)
 }
 
 /*
- * The inactive anon list should be small enough that the VM never has to
- * do too much work, but large enough that each inactive page has a chance
- * to be referenced again before it is swapped out.
- *
- * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
- * INACTIVE_ANON pages on this zone's LRU, maintained by the
- * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
- * the anonymous pages are kept on the inactive list.
- *
- * total     target    max
- * memory    ratio     inactive anon
- * -------------------------------------
- *   10MB       1         5MB
- *  100MB       1        50MB
- *    1GB       3       250MB
- *   10GB      10       0.9GB
- *  100GB      31         3GB
- *    1TB     101        10GB
- *   10TB     320        32GB
- */
-static void __meminit calculate_zone_inactive_ratio(struct zone *zone)
-{
-	unsigned int gb, ratio;
-
-	/* Zone size in gigabytes */
-	gb = zone->managed_pages >> (30 - PAGE_SHIFT);
-	if (gb)
-		ratio = int_sqrt(10 * gb);
-	else
-		ratio = 1;
-
-	zone->inactive_ratio = ratio;
-}
-
-static void __meminit setup_per_zone_inactive_ratio(void)
-{
-	struct zone *zone;
-
-	for_each_zone(zone)
-		calculate_zone_inactive_ratio(zone);
-}
-
-/*
  * Initialise min_free_kbytes.
  *
  * For small machines we want it small (128k min).  For large machines
@@ -6758,7 +6907,6 @@ int __meminit init_per_zone_wmark_min(void)
 	setup_per_zone_wmarks();
 	refresh_zone_stat_thresholds();
 	setup_per_zone_lowmem_reserve();
-	setup_per_zone_inactive_ratio();
 	return 0;
 }
 core_initcall(init_per_zone_wmark_min)